Tuyere construction for coalburning stokers



June 10 1941- c. cARLsoN :TAL 2,244,938

'runas cous'rnucmm FoR con-BURNING soxsns Filed may 18. lessi PatentedJunerlO, 1941- Turcas CONSTRUCTION Fon COAL- BURNING sroxnas Cornell'Carlson and Eugene M. Rosen, Chicago, Ill., asslgnors, by direct andmesne assignments, of one-fourth to Beatrice J. Carlson, and onefourthto George L. Coffey, both of Chicago, Ill.

Application May 18;'1939, Serial No. 274,344

7 Claims.

The present invention pertains to or relates to certain features ofimprovement and advantage in the tuyre-tops of Stoker-fedcoal-burningretorts, such as are commonly used in connect/ion withsteam-boilers or hot-water boilers, etc., and warm air furnaces.

In constructions of this type, as at present employed, trouble is moreor less commonly encountered by reason of the objectionable nature ofthe clinkers formed by the burned coal and which clinkers must` beperiodically removed from the fire-chamber of the furnace.

Not infrequently, the clinker forms in such a way as 'to close some ofthe air-ports, thus seriously interfering with the proper operation ofthe retort, and, in some cases, causing a melting of important andessential parts of the structure and, in otherA instances, effectingfusion of the clinker to the retort. l

Again, in such retorts of the prior art, it is impossible, for severalreasons, to burn satisfactorily the lower grades of coal.

Accordingly, one of the outstanding and paramount aims of the presentinvention is to provide a novel and improved retort structure whichovercomes the specified and other structural and functional defects oithe -retorts now in general.

use.

Our improvements comprise two principal features (a) the cooling of thetuyre-top of the retort by the circulation therethrough of water fromthe associated boiler, thus preventing such f top from heat damage, and,at the same time,

charged air in one direction inside of the retort and in the oppositedirection outside of the retort. which action. especially when combinedwith the cooling of the tuyre-top in the manner specified,` allowsefficient and satisfactory burning of the lowest grades of fuel.

Bv thus internally cooling the tuy're-top of the retort, the lowerconstant temperature assures the impossibility of the tuyre-member, orany i part of the retort, from becoming unduly heated or damaged orinjured by the heat.

Again, with the new structure, the clinkerforming material will not fuseto the burner or 'tuyre-top, the occurrence of which would necessitatepoking and pounding for the removal of the clinker, this being one ofthe major reasons for present-day burner and tuyre failures.

Further, burn-back is wholly avoided in the new construction becausethelatter allows coking of the coal in a, modified state only, and, as thefuel is fed upwardly mechanically, the temperature of the fuel ismaintained below that of ignition until the coal reaches the nre-line orair-ports, this feature also preventing a smokeback in the hopper, and,at the same time, eliminating the coke-tree in large degree, but rathermaintaining a substantially-level fire-bed.-

Additionally, our newly designed or modified arrangement andconfiguration of parts precludes the locking or termination of theoperation of the retort and its complementary or associated fuel-feedingStoker, which seriously objectionable occurrence takes place if theclinker is allowed to melt and run back into the retort while the stokeris workin-g, and then, when the Stoker ceases operation temporarily,such clinker hardens` or soli-dies in the retort, and thereafter, whenthe stoker again attempts to function, the coal-feed is blocked orlocked, causing the shearpin to break, or the clutch to be thrown out,resulting in extinguishment of the lire, andthe Stoker remains in suchinoperative condition, the air being blown uselessly, until the clinkeris pounded out of the retort with more or less dimculty and theshear-pin renewed.

Moreover, inasmuch as the air-delivery ports or passages circulate theair in the retort and outside of it in opposite directions, each in amore or less cyclonlc action, the combustion of the fuel is materiallyadded, and the rotary actionl of the air in the retort whirls the moltenslag to the top of the cooled tuyre, forming thereon a doughnut-likeclinker which can be removed with a minimum of effort and time and withno disturbance to the burning fuel.

To enable those acquainted with this art to understand the presentinvention fully, both from structural and functional standpoints, apresent preferred embodiment thereof has been illustrated in detail inthe accompanying drawing, to which reference should be had in connectionwith the following description, and, for simplicity, like referencenumerals have been employed in the views to designate the samestructural parts.

In this drawing:

Figure 1 is a central vertical section through the structure; and

f3, the former resting on the top of member I and the companion one |3bearing on the underlying ring I2.

Each such ring on its under surf-ace is equipped with a number of radialribs on which the ring is i supported, such ribs providing between thema corresponding series of radial-passages characterlzed I4 for ring I2and `I5 for ring |13.

-In order to maintain these rings in position,

l pair or plurality of upwardlylaring rings I2 and f.

passages 21 and 28 to produce the two reverselyl revolving whirlwindsinside and outside of the tuyre-ring, some of the air before reachingsuch groove or channel being delivered into the fuel in the retortthrough the passages I4 and I5.

'I'he retort tuyre-top 24 is hollow having with- .init the circularconduit or passage 3| connected through the bottom wall thereof by awater inletf-pipe 32 to the interior of the lower portion of the boiler(not shown) with which the fuel-burn ing retort is associated, wherebywater of relatively low temperature is fed from the lower part of theboiler into such passage 3|.

Such cooling water, after owing around the inside of the tuyre-topthrough conduit 3| in two paths in parallel arrangement, is dischargedback into the boiler at a higher level through a the upper outer marginof the member I0 has a circular rib I6 inside of which the ribs of ring`I2 fit, and the upper outer margin of ring |2 has an ups-tendingcircular rib I 1 which` accommodates inside of it the ribs of the upperring I3.

Surrounding and spaced from these superposed members I0, I2, and I3 is asuitably-supported cylindrical housing or casing I8 having on its underside a small number of vertically-apertured bosses I9, only one of whichis shown, and the holes through which each accommodates a stud or bolt2| tted in a hole in a corresponding projection or extension 22outstanding from the ,external surface of member I0, the head 23 on thelower end of such securing member 2| maintaining or holding member Il)in place, the top ends of such screws or bolts being received in4 iscrew-threaded holes in the lower part of the i novel, annular, tuyre,retort-top member 24,

thereby also keeping the latter xedly in position. This tuyre-member 2lhas a circular channel or groove 25 in its bottom face and such annularrecess receives in it, a round, upright, centering t rib 28 on the innerportion of the top end of casing I8, the element I8 solely supportingand carrying the part'24, all as is fully and clearly illustrated.

As is indicated in Figure 2, the bottom faceof the'ring-shaped top 24 isprovided with avseries of spaced, inwardly-directed, oblique passages21,

21 cut deeper into the bottom of the member than its circular channel 25and directly comv municating with such channel and with the open centerof such ring-shaped top member.

As is depicted, these passages are not radial with respect to the centerof element 24, lbut all of them aim to one side of such center so thatthe conjoint action of the plurality of air-jets `issuing from thepassages under pressure create a cyclonic effect or whirlwind of air inone circular direction around the center of such top, in the presentinstance counterclockwise in direction.

I'he underface of such tuyre-member 24 is supplied also with a circularseries of outwardlydirected oblique passages 28, 28 connecting groove 25with the exterior of the top, such passages being non-radial and equallyoblique, whereby air issuing therefrom under pressure creates awhirlwind around the outside of the retort in a clockwise direction ofcirculation the reverse of that of the inside whirlwind referred toabove.

3 Air under pressure, as from a fan or air-compressor (not shown), isfed through conduit 29 and up through the annular space between themembers 'I0 and I8 into groove 25 from which it is discharged throughthe two sets of deliverysecond pipe 33 connected to the side of passage3| at a point diametrically opposite the position where pipe 32 deliversits water thereinto.

'I'he specified flow of water is occasioned by a l thermo-syphon actionof well-understood principles, the water cooling the tuyre-top and itself becoming heated and returned to the boiler at such' raisedtemperature.

Thus the water cools the tuyre-elernent and augments or increases theWater-circulation in the boiler with direct beneficial results, in fact,increasing the heating capacity of the boiler.

From what precedes, it will be apparent that the water-cooling referredto, combined with the two whirlwinds of air, prevents theclinker-forming material from flowing down the tuyre-top and closing theair-delivery ports, and their united actions cause the clinker to'formabove the tuyre-top in ring-shape, andv of such character that it can bereadily removed periodically.

The new construction, because of such novel action, allows thesatisfactory burning of low grades of fuel which in manyfinstances is ofmaterial advantage and of substantial importance from an economicaspect.

Those skilled in this art will readily understand that the presentinvention is not necessarily limited to the details of constructionherein presented and that the construction may be `modified withinreasonable limits Without departure from the heartl and essence oftheinvention as defined by the appended claims and without the loss orsacrifice of its substantial benefits and advantages.

It may be understood thatthe Stoker-fed coalburning retort is not newexcept insofar as the tuyre-member or air-delivery top anditswaterconnections are concerned.

Whereas,ywe have shown and described the use of water for cooling thetuyre-top of the retort, it is to be understood that air under pressuremay be used instead for the same purpose, and, in the case of hot-airfurnaces, the air heated by flowing through such top may be deliveredinto the air-circulating current of the heating-system.

We claim:

l. In a tuyre-top for avstoker-fed coal-burning retort, said retort andtop when combined having registered central openings up through tion oftheir delivered air around the retort and g. In a tuyre-.top for astoker-fed coal-burning retort, said retort and top when combined havingregistered central openings up through which the fuel is fed, said tophaving means therein to receive air under pressure and a series ofinwardly-directed air-discharge passages delivering the air into thecoal in the retort and tuyre-top, the novel feature of theoblique-arrangement of said passages-tc cause coniointly a whirlwindcirculation of their delivered air around the interior of the retort andtop.

3. In a tuyre-top for a stoker-fed coal-burning retort, said retort andtop when combined having registered central. openings up through whichthe fuel is fed, such fuel passing over said top and down around theouter side thereof, said top having means therein to receive air underpressure, a series of inwardly-directed air-discharge passagesdelivering the air into the coal in the retort and tuyre-top, and `asecond series of outwardly-directed air-discharge'passages deliveringthe air into the coal surrounding the retort and tuyre-top. the novelfeatures of the oblique-arrangements of said passages of both series tocause whirlwind circulationsof their delivered air in and around theretort and top, said two whirlwind circulations being in reversedirections.

4. The mre-top set forth in claim 1 which is hollow to form acooling-water conduit therein,

- in combination with the novel features of a first pipe connecting oneportion of said conduit to the interior of the associated boiler toreceive water from the latter and a second pipe connecting anotherportion of said conduit to the interior of the boiler at a higher levelthan the corresponding connection therewith of said first pipe. wherebythe water flowing from the boiler and then back to the boiler throughsaid pipes and conduit cools said tuyre-top and increases thewater-circulation in the boiler.

5. The tuyre-top set forth in claim 2 which is hollow to form acooling-water conduit therein, in combination with the novel features ofa first pipe connecting one portion of said conduit to the interior ofthe' boiler heated by the fuel burning in said retort to receive waterfrom said boiler and a second pipe connecting another portion of saidconduit to the interior of said boiler at a higher level than thecorresponding connection therewith of said first pipe, whereby the waterflowingxfrom said boiler and then back to said boiler through said pipesand conduit cools said tuyre-top and increases the water.- circulationin the boiler.

6. The tuyre-top set forth in claim 3 which is hollow to form acooling-water conduit therein, in combination with the novel features ofa first pipe connecting one portion of. said conduit to the interior ofthe associated, boiler to receive water from the latter and a secondpipe connecting another portion of said conduit to the interior of theboiler at a higher level than the corresponding connection therewith ofsaid first pipe, whereby the water flowing from the boiler and then backto the boiler through said pipes and vconduit cools said tuyre-top andincreases the water-circulation in the boiler.

7. In a tuyre-top for a Stoker-fed coal-burning retort, said'retort andtop having registered central openings up through which the fuel is fed,said top having means to receive air under pressure, and a series ofair-discharge passages delivering such air from the top into the fuel,said tuyre-top being hollow to provide a waterconduit therein, the novelfeatures of such conduit being in endless form and in combination withan inlet-pipe connected to the interior of said conduit through thebottom-wall of said top and to the interior of the boiler heated by thefuel burning in said retort and top to convey water from said boiler tosaid conduit, and a discharge-pipe connected to the interior of saidconduit through the side-wall of said top and at a distance around saidtop from said inlet-pipe connection therewith and connected to theinterior of said boiler at a higher level than the correspondingconnection therewith of said inlet pipe, whereby water flowing from saidboiler through said inlet pipe passes through said tuyre-top conduit instreams in parallel relation and returns to the boiler through saiddischarge pipe, thus cooling said'l tuyre-top and

